Rotciv

What is the maximum current this cable can supply through the 5V wire?
The schematic shows an inductor in series with VBUS which becomes 5V.
Maybe in the next revision, have another leg of VBUS that connects directly to 5V.

Why is this board using a NPN transistor in common emitter configuration? With the 10K resistor, this board will only output around 1mA at 12 volts.
A PNP transistor will allow this board to drive a higher current load (up to the max Ic of the transistor) such as relays and motors.

SparkFun is an online retail store that sells the bits and pieces to
make your electronics projects possible. Whether it's a robot that can
cook your breakfast or a GPS cat tracking device, our products and
resources are designed to make the world of electronics more accessible.

In addition to products, SparkFun also offers
classes and online tutorials to help educate
individuals in the wonderful world of embedded electronics.